#define _CRT_SECURE_NO_WARNINGS 
#include <stdio.h>

int main() {
    int a, b, c;
    while ((scanf("%d%d%d", &a, &b, &c)) != EOF) {
        int t;
        if (a < b) {
            t = a;
            a = b;
            b = t;
        }
        if (a < c) {
            t = a;
            a = c;
            c = t;
        }
        if (b < c) {
            t = b;
            b = c;
            c = t;
        }
        if (b + c > a) {
            if (a == b && b == c)
                printf("Equilateral triangle!\n");
            else if (a == b || a == c || b == c)
                printf("Isosceles triangle!\n");
            else printf("Ordinary triangle!\n");
        }
        else printf("Not a triangle!\n");
    }
    return 0;
}